What does it mean?
C1168 is a Chassis (ABS, traction control, steering) fault code. It indicates: ABS Hydraulic Valve Power Relay Circuit Short to Battery .
Symptoms
- ABS warning lamp on, usually joined by the traction and stability control lamps
- ABS disabled: no pedal pulsing and no wheel speed control during a hard stop
- ABS pump or valve block may buzz or run briefly with the key off, and in bad cases the battery goes flat overnight
- Hydraulic unit gets warm to the touch after the car has been standing, because the valves stay energised
- Electronic brake force distribution and hill-start assist stop working and the red brake lamp may light
Likely causes
- Relay contacts welded closed, so the valve supply stays live all the time
- Wiring chafed against a permanently live cable or terminal, feeding battery voltage into the control line
- Water or corrosion inside the fuse and relay box bridging a live pin to the ABS control circuit
- Wrong relay fitted, or the relay pushed into the wrong slot after previous electrical work
- Aftermarket alarm, dashcam, trailer module or amplifier spliced into the ABS harness
- Damaged loom where it passes the battery, the starter feed or a high current junction
- Failed output driver inside the ABS control module reading or holding the line high
How to fix it
- Check for a parasitic drain and whether the hydraulic unit stays warm with the key off, which points straight at a stuck live feed
- Read all chassis codes; several valve circuits reporting short to battery together points at the shared supply, not at each valve
- Pull the relay, confirm it is the correct part in the correct slot, and check its contacts for welding with a meter
- Look inside the fuse and relay box for water tracks, corrosion and melted plastic between adjacent live pins
- With the relay and the ABS module connector removed, check for voltage on the control wire; any reading proves an external feed into the circuit
- Trace the harness back looking for chafe against a permanently live cable, and check every aftermarket splice in the engine bay
- Repair or reroute the damaged wiring, replace a welded relay, and treat the ABS module as the last suspect once the harness is proven clean